Many communities were started in Adjala by Irish Catholics who named their hamlets after their home towns in Ireland, or after prominent pioneer families who first settled the area.

The municipality has increasingly become home to residents who commute to the Greater Toronto Area.

Geographically the area is rolling countryside below the Niagara Escarpment to the west, with the Nottawasaga River cutting through it.

[3] The township comprises the communities of Achill, Airlie, Athlone, Ballycroy, Cedarville, Colgan, Connor, Everett, Glencairn, Hockley, Keenansville, Lisle, Loretto, Rosemont, Sheldon, Tioga and Tuam.

It has one of the oldest and most famous taverns in Simcoe County, the Loretto Inn.